Thick-billed Warbler (Arundinax aedon)
Illustration redrawn by AI from a real photograph

Thick-billed Warbler

Arundinax aedon (Pallas, 1776)

16–18 cmLength22 gWeight

It is a large reed warbler with a plain rufous back, a rounded forehead and a short, pointed bill.

Busiest months: December–February and May · Most records: Thailand, China, India

Least Concern

How to identify

Field marks

  1. Rufous back without markings
  2. Yellowish-brown underparts, with few conspicuous plumage features overall
  3. Rounded forehead
  4. Short, pointed bill

Male, female and young

Sexes identical; juvenile has richer yellowish-brown underparts.

Voice

Fast, loud song resembles that of Marsh Warbler, with much mimicry and whistles typical of reed warblers.

Where and when it's recorded

Thick-billed Warbler has been recorded at 581 of the 8,171 birding hotspots we track, in 15 countries and regions.

Records by month Northern Hemisphere

Where it's recorded most

  1. Muravyevka ParkRussia309 records
  2. Sangla and AreaNepal225 records
  3. Khurkh Bird Ringing Station, Khentii, MNMongolia213 records
More places
  1. Nam Kham Nature ReserveThailand203 records
  2. GKVK CampusIndia190 records
  3. Kaeng Krachan NP – km 9 vicinityThailand143 records
  4. Koshi Tappu Wildlife ReserveNepal126 records
  5. Nanpu MudflatChina122 records
  6. Taksin Maharat NP – headquarters vicinityThailand118 records
  7. Chiang Mai University – Mae Hia Agricultural CollegeThailand114 records

Countries and regions with the most records

ThailandChinaIndiaNepalLaosCambodiaMongoliaRussia

eBird records via GBIF up to 2024-12-31. A record means someone listed it; more records partly mean more birders, not more birds.

About

The thick-billed warbler (Arundinax aedon) breeds in the temperate east Palearctic, from south Siberia to west Mongolia. It is migratory, wintering in tropical South Asia and South-east Asia. It is a very rare vagrant to western Europe.

Excerpt from Wikipedia, CC BY-SA 4.0 · authors · Read more on Wikipedia

Questions

How big is the Thick-billed Warbler?

The Thick-billed Warbler is about 16–18 cm long and weighs around 22 g.

Where does the Thick-billed Warbler live?

Its breeding range: Palearctic: north-central, northeastern. It is most often recorded in Thailand, China and India.

When is the best time to see the Thick-billed Warbler?

At the hotspots we track, it is recorded most in January, February, May and December (Northern Hemisphere).

Is the Thick-billed Warbler endangered?

The IUCN Red List classifies the Thick-billed Warbler as Least Concern.

What does the Thick-billed Warbler eat?

Main food: Insects & other invertebrates.

What family is the Thick-billed Warbler in?

It belongs to the family Reed Warblers & Allies (Acrocephalidae), order Passerines (Passeriformes).

At a glance

Length
16–18 cm
Weight
22 g
Habitat
Shrubland
Diet
Insects & other invertebrates
Lifestyle
Perches in trees
Migration
Migratory
Conservation
Least Concern
More measurements
Wing
78 mm
Tail
79 mm
Bill
18 mm
Tarsus
26 mm

Averages from the AVONET dataset; length from field guides where available.

Range

Palearctic: north-central, northeastern

Breeding range, IOC World Bird List 15.2

Subspecies · 1
  • Arundinax aedon rufescens e Siberia, ne Mongolia and ne China | non-breeding: to Indochina

Classification

Order
Passerines Passeriformes
Family
Reed Warblers & Allies Acrocephalidae
Genus
Arundinax

More from the family Reed Warblers & Allies

Grauer's WarblerGrauer's WarblerGraueria vittataMalagasy Brush WarblerMalagasy Brush WarblerNesillas typicaSubdesert Brush WarblerSubdesert Brush WarblerNesillas lantziiAnjouan Brush WarblerAnjouan Brush WarblerNesillas longicaudataGrande Comore Brush WarblerGrande Comore Brush WarblerNesillas brevicaudataMoheli Brush WarblerMoheli Brush WarblerNesillas mariaeBasra Reed WarblerBasra Reed WarblerAcrocephalus griseldisCape Verde WarblerCape Verde WarblerAcrocephalus brevipennisGreater Swamp WarblerGreater Swamp WarblerAcrocephalus rufescensLesser Swamp WarblerLesser Swamp WarblerAcrocephalus gracilirostris
Thick-billed Warbler

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Free to use with credit: “Illustration: Bird Album (birdalbum.com)”. Drawn by AI from a reference photo by ThuZar. ↗

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